A mobile phone, suspected to have been used by the accused to click photos of the victim, has been seized. "Only one photograph was said to have been clicked but even that is not available now. We will try to retrieve it," he said.

The Police Commissioner said experts from the Central Forensic Science Laboratory and Gujarat Forensic Science Laboratory would assist the city police in gathering "clinching evidence" against the accused. While the team from CFSL has already arrived, the one from Gujarat will reach soon.

Singh said the process of setting up a fast track court to try the case and appointing a prosecutor is underway and chargesheet would be filed at the earliest.

Chief Minister Prithviraj Chavan had on Sunday said eminent criminal lawyer Ujjwal Nikam, who was the public prosecutor in the 1993 Bombay serial blasts case and 26/11 attacks case, would lead the prosecution in the gang-rape case of the 23-year-old photojournalist.

The officer said three of the accused--Chand Bahu Sattar Sheikh, Vijay Jadhav and Mohammed Qasim--had criminal records. While the first two had one case of theft each registered against them in 2011, Qasim had three cases of theft and one of robbery.